1. Technical Field of the Invention
This invention relates to liquid processing apparatus and method for applying a designated liquid processing on a variety of substrates, such as semiconductor wafer and LCD substrate.
2. Description of the Related Art
In general, the manufacturing process of semiconductor devices employs a wafer liquid processing apparatus that processes semiconductor wafers (called as “wafer” hereinafter) as the substrates with processing liquids, such as specified chemical and deionized water (pure water), in order to remove particles, organic contamination, contamination such as metallic impurities, organic matter, oxide film, etc. from the wafers.
As the wafer liquid processing apparatus, for example, there is known a batch type processing apparatus that accommodates a number of wafers in a liquid processing chamber and processes the wafers in batch. In this apparatus, it is generally carried out to process the wafers in increments of carriers (wafer containers). Since the carrier is formed) to accommodate a predetermined number of substantially-parallel wafers, for example, twenty-five parallel wafers at regular intervals, the liquid processing of the wafers is carried out as the following steps of: first picking up these wafers from the carrier at a time; next transporting the wafers to a rotor; and subsequently supplying a processing liquid to the wafers while rotating the rotor. Noted that an interval (pitch) of the wafers in the rotor is equal to the interval of the wafers in the carrier.
In the conventional liquid processing method mentioned above, however, it is difficult to increase the throughput capacity of the apparatus because the number of wafers to be processed in one batch processing is no more than the number of wafers accommodated in one carrier. In this view, for example, it is expected to make one rotor retain the wafers of two carriers for one batch processing. In this case, if the wafers of two carriers are once accommodated in one rotor at the same pitch as the pitch of the wafers in one carrier, there crops up various problems: jumboized rotor, jumboized chamber to accommodate the rotor, increased consumption of processing liquid in relation to the jumboized chamber, etc.
In the conventional liquid processing apparatus where wafers are dipped in the processing liquid stored in a tank etc. without rotating the wafers, there is known a liquid processing apparatus that applies the liquid processing on the wafers carried half of the pitch of wafers in the carrier. To the contrary, as for the liquid processing while rotating the wafers, it has not been carried out to apply the liquid processing on the wafers carried half of the pitch of wafers in the carrier.
Further, when processing the wafers accommodated in two carriers in one batch processing, it is hard to increase the total throughput (including the transportation of the carriers) in spite of improvement in the throughput of the liquid processing unless the transportation of the carriers accommodating the wafers is executed effectively.
Additionally, since the wafers are discharged from the carrier at a time and successively loaded on the rotor in the conventional liquid processing method, the pitch of the wafers carried on the rotor is always constant. Thus, it is impossible to perform the liquid processing while allowing the rotor to carry the wafers in optional pitch. Moreover, since the wafers have been processed in units of carrier in accordance with the conventional liquid processing method, it is impossible to pick up an optional carrier from plural carriers for one batch processing.